All About the Swine Flu Vaccine

Whether you're expecting to expect, already expecting, or have (little or big) kids in the house, you've definitely got lots of questions about the swine flu vaccine. To the rescue: Our swine flu vaccine guide, where you'll find all the answers.

Do you have more questions than answers about the new swine flu vaccine? What parent (or parent-to-be) doesn’t this season? You’ve got questions about the vaccine’s safety — for you, your baby-to-be, or the baby (of any age) who’s already here. Questions about where to get the vaccine (especially when you can’t find a doctor’s office or clinic in your area that’s offering it). About which vaccine your child should get. About which vaccine you should get. About all those alarming reports on side effects (or are they rumors?) you’ve read online or heard on TV — or overheard at the playground. Ready to clear up all the confusion? Here are the answers to your questions, the relief for your worries, and everything you want to know about the H1N1 (swine flu) vaccine:

Vaccine Basics

Q: Is there a difference between the H1N1 vaccine and the seasonal flu one? A: Yes — a big difference: They are two completely separate vaccines. Every year, drug companies, working with the Centers for Disease Control and Prevention (CDC), develop and distribute a seasonal-flu vaccine that protects against whatever strain of influenza will be most prevalent (and virulent) that year. This year, experts also developed the H1N1 vaccine to protect people against a brand-new strain of flu, the 2009 H1N1 virus (aka swine flu), because it appeared on the scene too late to be included in this year’s seasonal flu vaccine. Since each vaccine immunizes against a different virus (the seasonal vaccine can’t protect you against the H1N1 flu virus, and the H1N1 vaccine can’t protect you against the seasonal flu virus), the CDC and other health experts are recommending both vaccines. The good news: You can get both vaccines at the same time — as long as they’re not both nasal spray vaccines (you can get both in shot form, or one in shot form and one in nasal spray form, but if you’re having both in nasal spray form they’ll be spaced about four weeks apart).

Q: Should my family get the nasal spray version of the H1N1 vaccine or the shot? A: The H1N1 vaccine, like the seasonal flu vaccine, is available in injectable form (which contains an inactivated virus) and nasal spray form (which contains a live, but weakened virus). Not a fan of needles (and who is)? Keep in mind that certain higher-risk groups aren’t eligible for the nasal spray. Babies and toddlers under two, expectant moms, and anyone (child or adult) who has a chronic health condition (like asthma, diabetes, or heart disease) or a compromised immune system should receive the injectable vaccine, not the nasal spray.

Q: Can I get the swine flu vaccine and the seasonal flu vaccine at the same time? A: If you’re getting the injectable vaccine (which you will if you’re pregnant or have an underlying health condition), you can get both the regular flu and the H1N1 flu shots at the same time. But if you’re getting the nasal spray vaccines, you’ll have to line up twice — with the sprays spaced four weeks apart. Want to save time? Get both vaccines in shot form, or one as a shot and one as a nasal spray.

Q: Is there anyone who shouldn’t be vaccinated? A: There are some exceptions to the vaccination-for-everyone recommendation, just as there are every flu season. People who shouldn’t get either flu vaccine include:

Those who’ve had a severe reaction to a previous flu shot

Babies younger than six months of age

Anyone who’s sick or has a fever (the doctor can decide if you’re too sick for the shot)

Of course, check with a doctor first if you or anyone in your family falls into one of these groups.

Q: What are the side effects of the H1N1 vaccine? A: Side effects of the H1N1 vaccine are similar to those of the seasonal-flu vaccine and are most often very mild. They can include localized (at the site of the shot) redness, soreness, or swelling. Some flu (H1N1 or seasonal) vaccine recipients may also develop a headache, nausea, fatigue, some muscle pain, or even a slightly elevated temperature. Severe reactions are rare.

Q: The new swine flu vaccine hasn’t been tested very long. How do I know it is safe? A: Experts — from the CDC to the Food and Drug Administration, from the American College of Obstetricians and Gynecologists (ACOG) to the American Academy of Pediatrics (AAP) — are confident that the H1N1 vaccine is just as safe as the seasonal-flu vaccine (which has a long record of safety and effectiveness not only in the general population but also in pregnant women and children). That’s because the 2009 H1N1 vaccine and the seasonal flu vaccines are made and tested the same way, just with a different flu strain. In other words, this new vaccine isn’t completely new at all. It’s basically a laboratory tweak of the yearly seasonal vaccine, specifically designed to combat the brand-new H1N1 virus (the seasonal vaccine is also fine-tuned for each year’s virus). If you have any concerns about the vaccine’s safety, discuss it with your doctor.

Q: I’m still worried about the swine flu vaccine’s rush to market. I heard about the swine flu shot in the 1970s when people died or were paralyzed from the shot. A: The 1976 swine flu vaccine and the current swine flu vaccine aren’t similar at all (and in fact, the strains of flu themselves are different, too). The 1970s shot was formulated differently, and vaccine manufacturers have improved their processes since then. This swine flu vaccine is formulated in the exact same way (and in the same facilities) as the seasonal flu vaccine (just with a different flu strain), which has a long record of safety.

Q: I’ve heard that the vaccine contains thimerosal. What is that exactly and is it safe? A: Thimerosal is a preservative (containing mercury) that has been used in vaccines since the 1930s to avoid contamination, though it hasn’t been added to vaccines (other than the flu vaccine) since 2001. Myths and rumors about an association between the thimerosal in vaccines and harmful side effects (including illnesses and such developmental disorders as autism) have been thoroughly debunked again and again by numerous large-scale studies — as well as by all reputable health organizations.

Multidose vials of H1N1 vaccine — like seasonal flu vaccine — typically contain small amounts of thimerosal (to prevent the vial from becoming contaminated), while single doses of the vaccine don’t require the preservative. The nasal spray, which always comes in single doses, doesn’t contain thimerosal, either. Pregnant women and children can get the vaccine with or without thimerosal (if it’s available) — but it’s important to keep in mind that there is absolutely no evidence that exposure to the minuscule amount of this preservative poses any risk to an expectant mom, an unborn baby, or children who receive either flu vaccine. To help you keep any unfounded fears you may have about thimerosal in perspective, think about it this way: One dose of the flu vaccine with thimerosal contains approximately 25 micrograms of mercury. Sounds like a lot, until you consider that the tuna-fish sandwich you ate for lunch (or served to your child) contains about 28 micrograms of mercury.

If you’re still concerned, ask your practitioner if you (and/or your child) can receive a dose of thimerosal-free flu vaccine. Anyone who wants a thimerosal-free vaccine can get one, assuming your doctor or clinic has enough on hand.

Q: Does the swine flu vaccine contain squalene? What is that, and is it safe? A: Squalene is a natural organic compound that is sometimes added to vaccines as an adjuvant (something that enhances the immune response to a vaccine, allowing smaller quantities of the vaccine to be given). Only one vaccined called FLUAD is sold with an adjuvant, though it's only licensed for those 65 and over. And if you’re still wondering about the safety of squalene or other adjuvants (just because), wonder no more: According to the CDC, squalene isn’t harmful at all.

Q: My doctor’s office still doesn’t have the swine flu vaccine. I’m worried — will there be enough swine flu vaccine for everyone? A: The first doses of the nasal spray became available in early October; the first doses of the shot became available a week later, and more doses of both are becoming available every week. What’s the hold up? Producing a flu vaccine takes time, and both the production and distribution of this vaccine has been slower than expected. But the health powers that be — from the CDC to the HHS (Department of Health and Human Services) — are reporting that there will be enough supply of both the injectable vaccine and the nasal-spray vaccine to keep up with demand, eventually. While there’s still limited availability, they’re recommending that the following higher-risk groups move to the head of the line for their vaccinations (and note that pregnant women, children under two, and anyone with an underlying medical condition can’t receive the nasal spray, only the shot):

Pregnant women

People who live with or care for children younger than six months of age

Children and young adults between the ages of six months to 24 years old

People 25 to 64 years old who have chronic medical conditions

Q: What should I do if the H1N1 vaccine isn’t available in my area yet? A: Every state is developing a vaccine delivery plan to make sure that people can get the swine flu shot in a variety of places — vaccine clinics organized by local health departments, doctors’ offices, schools, pharmacies, and even some workplaces. In the meantime, ask your doctor’s office or local clinic to find out when they expect their supply and when you can make an appointment — or get in line — to receive it. You can also go to the CDC Web site and click here to check the latest information on vaccine supply. If you’re in a higher-risk group, it’s worth your while to try to get vaccinated earlier rather than later.

Q: I think I may have had swine flu. Do I still need to be vaccinated? A: The problem is, the symptoms of swine flu are similar to those of seasonal flu (though the H1N1 virus has been associated with more vomiting and diarrhea than the seasonal flu) and can also be pretty close to symptoms of some other viral or bacterial infections. So unless testing has confirmed that you’ve had swine flu (and at this point, only those who have been hospitalized with complications are being tested), it’s unlikely you’d ever have an official diagnosis of H1N1. In fact, the vast majority of those hit with flu symptoms this season won’t definitively know what hit them. Not sure? Want to play it safe? It’s a good idea to be vaccinated anyway, particularly if you’re expecting or a newly delivered mom (or you have a baby under the age of six months at home) or are otherwise at high risk. Ask your doctor for specific recommendations. By the way, even if you did have swine flu before — and already have some existing immunity to the virus — there’s no harm in getting vaccinated.

Q: Can I still catch swine flu if I get the vaccine? A: With the seasonal flu, experts do their best to match the flu vaccine with the flu strain that is circulating — and they believe the H1N1 vaccine is well matched to the swine flu and therefore effective against it. While it’s possible you could still catch swine flu even if you received the vaccination, it isn’t likely (and if you do catch it, it’s bound to be only a mild case). Keep in mind that it can take up to two weeks after vaccination for immunity (those vital antibodies) to develop, and younger children and babies will require two doses to build up their H1N1 immunity.

Q: Will I have to get the vaccine again next year? A: Yes. Flu strains change from year to year. But here’s something to look forward to: Next year’s H1N1 flu strain will be incorporated into the seasonal-flu vaccine…so you won’t need two separate flu vaccines.

Q: How much does the vaccine cost? If it’s not free, will insurance cover it? A: The vaccine itself is free. And although your doctor or a clinic may charge a fee for administering the vaccine, many health-care companies are covering that fee.

Q: Is the vaccine mandatory? A: No. But it is recommended — especially for those at high risk.

Pregnancy and the H1N1 Vaccine

Q: I’m pregnant. Why should I get vaccinated? A: The CDC, ACOG, the American Academy of Family Physicians (AAFP), and the World Health Organization (WHO) have had a long-standing recommendation that women who will be pregnant during flu season (which typically runs from October to mid-May) receive a seasonal-flu vaccine. That’s because if you get the flu while you’re pregnant, you’re more likely to have serious complications, such as pneumonia, which can also affect the health of your baby. So far, it appears that the H1N1 virus poses even more risk to expectant moms and their babies than the seasonal flu. Which is why experts are now recommending that all pregnant women step to the front of the line for their H1N1 and seasonal flu vaccines. While the two vaccines are manufactured in the same way, they’re made with different viruses; so in order to protect yourself and your baby fully against seasonal flu and swine flu, you’ll need both vaccines this year. Another very important plus of rolling up your maternity shirtsleeve now: The anti-flu antibodies that you develop after getting the shot are passed to your baby, providing immunity until about age six months, at which point your little one can be vaccinated, too. Hoping to avoid the needles? Not so fast…expectant moms can’t receive the nasalspray vaccine.

Q: Is the H1N1 flu shot safe for pregnant women? A: Experts are confident that the H1N1 flu shot is just as safe as the seasonal flu shot is for pregnant women (and for kids). The 2009 H1N1 vaccine and the seasonal flu vaccines are made and tested the same way, in the same laboratories. Pregnant women have been given the seasonal flu vaccine since the late 1950s with little or no adverse events, and the H1N1 vaccine is formulated in the exact same way (it’s just a different flu strain).

Q: I thought I had to wait until my second trimester to get the swine flu shot. Is this true? A: This is pure flu fiction — one of the many unfounded rumors feverishly making the rounds this busy flu season. Here’s the most current flu fact: You can step to the front of the line as soon as your home pregnancy test reveals the good news — and you should line up also if you’re trying to conceive or will be trying this flu season. Both the CDC and ACOG recommend the shot for every pregnant woman during flu season, no matter which trimester she’s in. And here’s some time-saving news: Like everyone else, you can get both the seasonal-flu shot and the H1N1 flu shot at the same sitting (one in each arm!) if both are available. Just gave birth? Step to the head of the line, too. Your immune system still thinks it’s pregnant — you’ll have the same risks as you did when you were pregnant for up to two weeks after you give birth. (The same principle applies to women who’ve just suffered a pregnancy loss — you’re considered high risk for the first two weeks after your loss.)

Q: Can I get the nasal spray version if I’m pregnant? A: No. Since the nasal flu vaccine is made with a live (though weakened) virus, experts recommend that only people with robust immune systems get the nasal spray — and no matter how healthy you are (and even if you’re positively radiating good health), your immune system isn’t up to par when you’re pregnant. Exposing a mom-to-be (whose immune system is somewhat suppressed and who is carrying a fetus with a still-developing immune system) to a live virus isn’t the best bet. For this reason, it’s recommended that pregnant women skip the nasal spray and opt for the shot instead — but be aware that it’s perfectly safe for those who live with an expectant mom to receive the spray. Assuming you’re otherwise healthy, it’s fine to get the spray vaccine after two weeks postpartum — even if you’re nursing your newborn.

Q: I’m pregnant and wondering what the risks of miscarriage are if I get the H1N1 flu. What are the risks of miscarriage from the vaccine? A: While the H1N1 virus has been linked to a higher rate of complications for pregnant women, it hasn’t been associated with a higher rate of miscarriage. When there is a link between the flu (seasonal or swine) and miscarriage, it’s usually thought to be related to a prolonged high fever — another good reason to bring down fevers quickly during pregnancy (with Tylenol or as directed by your practitioner) and to call your doctor right away for evaluation and treatment if you’re expecting and experiencing symptoms of flu. Also good to know: Experts believe that there is no increased risk of miscarriages from the H1N1 vaccine or regular seasonal-flu vaccine.

Children and the H1N1 Vaccine

Q: Is the swine flu vaccine safe for children? A: Yes — and even though it’s a brand-new vaccine, it’s been made in the exact same way as the seasonal flu vaccine, which has a long safety record. Need another reason to get your little one vaccinated? In the unlikely event that your child is felled by the H1N1 flu after receiving a shot (or spray if he or she’s over two and healthy), then it is bound to be only a mild case. And to put your mind at rest even further: The CDC and FDA have set up a task force of medical experts to monitor any unexpected side effects or reactions to the vaccine.

Q: What side effects can I expect after my child receives the swine flu vaccine? A: Side effects of the H1N1 vaccine, if any, are mild — and similar to side effects you might expect in your child after a seasonal flu vaccine. Chances are you’ll be given a list of potential side effects when your child receives the vaccine, but typically they include a sore arm, a little redness, and sometimes even a low-grade fever.

Q: Should all children get the swine flu shot? A: The CDC is recommending vaccination for all children over the age of six months, even those without any risk factors for complications. While the vast majority of kids who’ve come down with H1N1 flu have had mild cases — and recovered quickly — there have been an unexpected number of complications and hospitalizations in children, teens, and young adults. Experts also suspect that if high numbers of kids and teens get vaccinated, it will reduce the spread of flu germs (swine and seasonal) to everyone in the community — parents and teachers included. This is one reason why experts are making a big push to get schools involved in vaccinating all their students.

Q: I heard that younger children have to get two shots to be protected against the H1N1 flu. Is this true? A: Though no parent likes to see a needle headed toward her little one once…never mind twice (that’s twice the tears!), it is true — younger children need that second shot to be fully protected. Here’s what the CDC is recommending this flu season for specific age groups (both for the H1N1 and seasonal-flu vaccines):

If your child is younger than six months: Babies this age can’t be vaccinated against swine or seasonal-flu vaccine — which is why those who care for them or live with them should be (and why moms-to-be should be vaccinated, too).

If your child is six months to nine years old: These little (but not as little) ones will need two doses of the H1N1 flu shot, separated by at least four weeks. If your child is getting a seasonal flu shot for the first time, and is eight years old or younger, he or she will also need two separate shots (separated by four weeks). Luckily, your child will be able to get both the seasonal and swine flu vaccines at the same time (meaning only two trips to the doctor).

If your child is ten or older: Your older tween or teen will need only one dose of the swine flu shot and one dose of the seasonal flu vaccine, even if your child is a flu vaccine first-timer.

Q: My son hates needles! Can he get the nasal spray version? A: What little one looks forward to getting a shot? And for that matter, what adult does? The nasal spray version does sound like the perfect vaccine match for the needle-phobic of any age. But not all kids can safely turn up their little noses for it. The nasal spray flu vaccine (both H1N1 and seasonal) is made from a live (but weakened) virus — unlike the shot, which is made from an inactivated virus. Is your child eligible for the nasal spray? He is not if he:

Is under two years old

Has a chronic respiratory condition (like asthma) or any other underlying medical condition (like diabetes), no matter what his age

Still not sure if your older-than-two-year-old is nasal-spray qualified? Check with his doctor. Also keep in mind that the nasal sprays come with strings (if not needles) attached. That’s because he can’t get both the seasonal and the H1N1 nasal-spray vaccines at the same visit; instead, they’ll have to be spaced four weeks apart (and that will leave him unprotected against one a month longer).

Q: I’m breastfeeding. Can I get the H1N1 vaccine? A: Not only can you get the shot, but you definitely should — especially if your baby still hasn’t celebrated that six-month birthday yet. Until then, your little bundle of joy (and his or her very immature immune system) relies on your breastmilk for antibodies. Those powerful germ-fighters are plentiful in your breastmilk already — but they may become even more plentiful when you receive the vaccine and develop antibodies specifically to fend off this H1N1 virus. What’s more, if you don’t get sick — you can’t get your baby sick. That’s why it’s recommended that anyone who lives with or cares for a baby who’s younger than six months should get vaccinated against the H1N1 vaccine (and the seasonal-flu vaccine). More good flu-vaccine news: Both the shot and the spray are perfectly safe for breastfeeding moms.

Q: My child has an egg allergy, and I heard he can’t get the vaccine. What should I do to protect him? A: Since the swine flu vaccine (like the seasonal flu vaccine) is formulated using hen’s eggs, anyone (child or adult) with a known egg allergy shouldn’t receive it — and that goes for both the injected and the nasal spray vaccinations. (Make sure to check with your doctor first about your child’s specific case.) To protect your egg-allergic child as much as possible, follow healthy hygiene habits, and make sure that everyone else in your family is vaccinated.

From the What to Expect editorial team and Heidi Murkoff, author of What to Expect When You're Expecting. Health information on this site is based on peer-reviewed medical journals and highly respected health organizations and institutions including ACOG (American College of Obstetricians and Gynecologists), CDC (Centers for Disease Control and Prevention) and AAP (American Academy of Pediatrics), as well as the What to Expect books by Heidi Murkoff.